-(* Copyright (C) 2000, HELM Team.
- *
- * This file is part of HELM, an Hypertextual, Electronic
- * Library of Mathematics, developed at the Computer Science
- * Department, University of Bologna, Italy.
- *
- * HELM is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * HELM is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with HELM; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- *
- * For details, see the HELM World-Wide-Web page,
- * http://cs.unibo.it/helm/.
- *)
+(*
+ ||M|| This file is part of HELM, an Hypertextual, Electronic
+ ||A|| Library of Mathematics, developed at the Computer Science
+ ||T|| Department, University of Bologna, Italy.
+ ||I||
+ ||T|| HELM is free software; you can redistribute it and/or
+ ||A|| modify it under the terms of the GNU General Public License
+ \ / version 2 or (at your option) any later version.
+ \ / This software is distributed as is, NO WARRANTY.
+ V_______________________________________________________________ *)
(* $Id$ *)
let lift_from k n =
let rec liftaux k = function
- | NCic.Const _
- | NCic.Sort _ as t -> t
- | NCic.Rel m ->
- if m < k then NCic.Rel m
- else NCic.Rel (m + n)
- | NCic.Meta (i,(m,l)) when k <= m -> NCic.Meta (i,(m+n,l))
+ | NCic.Rel m as t -> if m < k then t else NCic.Rel (m + n)
+ | NCic.Meta (i,(m,l)) as t when k <= m ->
+ if n = 0 then t else NCic.Meta (i,(m+n,l))
| NCic.Meta (_,(m,NCic.Irl l)) as t when k > l + m -> t
| NCic.Meta (i,(m,l)) ->
let lctx = NCicUtils.expand_local_context l in
- NCic.Meta (i, (m, NCic.Ctx (List.map (liftaux (k-m)) lctx)))
+ NCic.Meta (i, (m, NCic.Ctx (NCicUtils.sharing_map (liftaux (k-m)) lctx)))
| NCic.Implicit _ -> (* was the identity *) assert false
- | NCic.Prod (n,s,t) -> NCic.Prod (n, liftaux k s, liftaux (k+1) t)
- | NCic.Lambda (n,s,t) -> NCic.Lambda (n, liftaux k s, liftaux (k+1) t)
- | NCic.LetIn (n,ty,te,t) ->
- NCic.LetIn (n, liftaux k ty, liftaux k te, liftaux (k+1) t)
- | NCic.Appl l -> NCic.Appl (List.map (liftaux k) l)
- | NCic.Match (r,outty,t,pl) ->
- NCic.Match (r,liftaux k outty,liftaux k t, List.map (liftaux k) pl)
+ | t -> NCicUtils.map (fun _ k -> k + 1) k liftaux t
in
liftaux k
;;
(* if avoid_beta_redexes is true (default: false) no new beta redexes *)
(* are generated. WARNING: the substitution can diverge when t2 is not *)
(* well typed and avoid_beta_redexes is true. *)
-let rec psubst ?(avoid_beta_redexes=false) delift lift_args args =
+(* map_arg is ReductionStrategy.from_env_for_unwind when psubst is *)
+(* used to implement nCicReduction.unwind' *)
+let rec psubst ?(avoid_beta_redexes=false) delift lift_args map_arg args =
let nargs = List.length args in
let rec substaux k = function
- | NCic.Rel n as t ->
- (match n with
- | n when n >= (k+nargs) -> if delift then NCic.Rel (n - nargs) else t
- | n when n < k -> t
- | n (* k <= n < k+nargs *) ->
- (try lift (k+lift_args) (List.nth args (n-k))
- with Failure _ -> assert false))
- | NCic.Meta (_,(m,_)) as t when m >= k + nargs - 1 -> t
- | NCic.Meta (_,(m,NCic.Irl l)) as t when k > l + m -> t
- | NCic.Meta (i,(m,l)) ->
- let lctx = NCicUtils.expand_local_context l in
- (* 1-nargs < k-m, when <= 0 is still reasonable because we will
- * substitute args[ k-m ... k-m+nargs-1 > 0 ] *)
- NCic.Meta (i,(m, NCic.Ctx (List.map (substaux (k-m)) lctx)))
- | NCic.Sort _ as t -> t
- | NCic.Implicit _ -> assert false (* was identity *)
- | NCic.Prod (n,s,t) -> NCic.Prod (n, substaux k s, substaux (k + 1) t)
- | NCic.Lambda (n,s,t) -> NCic.Lambda (n, substaux k s, substaux (k + 1) t)
- | NCic.LetIn (n,ty,te,t) ->
- NCic.LetIn (n, substaux k ty, substaux k te, substaux (k + 1) t)
- | NCic.Appl (he::tl) ->
- (* Invariant: no Appl applied to another Appl *)
- let rec avoid he = function
- | [] -> he
- | arg::tl as args->
- (match he with
- | NCic.Appl l -> NCic.Appl (l@args)
- | NCic.Lambda (_,_,bo) when avoid_beta_redexes ->
- avoid (psubst ~avoid_beta_redexes true 0 [arg] bo) tl
- | _ as he -> NCic.Appl (he::args))
- in
- let tl = List.map (substaux k) tl in
- avoid (substaux k he) tl
- | NCic.Appl _ -> assert false
- | NCic.Const _ as t -> t
- | NCic.Match (r,outt,t,pl) ->
- NCic.Match (r,substaux k outt, substaux k t, List.map (substaux k) pl)
+ | NCic.Rel n as t ->
+ (match n with
+ | n when n >= (k+nargs) ->
+ if delift && nargs <> 0 then NCic.Rel (n - nargs) else t
+ | n when n < k -> t
+ | n (* k <= n < k+nargs *) ->
+ (try lift (k-1+lift_args) (map_arg (List.nth args (n-k)))
+ with Failure _ -> assert false))
+ | NCic.Meta (i,(m,l)) as t when m >= k + nargs - 1 ->
+ if delift && nargs <> 0 then NCic.Meta (i,(m-nargs,l)) else t
+ | NCic.Meta (i,(m,(NCic.Irl l as irl))) as t when k > l + m ->
+ if delift && nargs <> 0 then NCic.Meta (i,(m-nargs,irl)) else t
+ | NCic.Meta (i,(m,l)) ->
+ let lctx = NCicUtils.expand_local_context l in
+ (* 1-nargs < k-m, when <= 0 is still reasonable because we will
+ * substitute args[ k-m ... k-m+nargs-1 > 0 ] *)
+ NCic.Meta (i,(m, NCic.Ctx (NCicUtils.sharing_map (substaux (k-m)) lctx)))
+ | NCic.Implicit _ -> assert false (* was identity *)
+ | NCic.Appl (he::tl) as t ->
+ (* Invariant: no Appl applied to another Appl *)
+ let rec avoid he' = function
+ | [] -> he'
+ | arg::tl' as args->
+ (match he' with
+ | NCic.Appl l -> NCic.Appl (l@args)
+ | NCic.Lambda (_,_,bo) when avoid_beta_redexes ->
+ (* map_arg is here \x.x, Obj magic is needed because
+ * we don't have polymorphic recursion w/o records *)
+ avoid (psubst
+ ~avoid_beta_redexes true 0 Obj.magic [Obj.magic arg] bo) tl'
+ | _ -> if he == he' && args == tl then t else NCic.Appl (he'::args))
+ in
+ let tl = NCicUtils.sharing_map (substaux k) tl in
+ avoid (substaux k he) tl
+ | t -> NCicUtils.map (fun _ k -> k + 1) k substaux t
in
substaux 1
;;
-let subst ?avoid_beta_redexes arg = psubst ?avoid_beta_redexes true 0 [arg];;
+let subst ?avoid_beta_redexes arg =
+ psubst ?avoid_beta_redexes true 0 (fun x -> x)[arg];;
(* subst_meta (n, Some [t_1 ; ... ; t_n]) t *)
(* returns the term [t] where [Rel i] is substituted with [t_i] lifted by n *)
let subst_meta = function
| m, NCic.Irl _
| m, NCic.Ctx [] -> lift m
- | m, NCic.Ctx l -> psubst false m l
+ | m, NCic.Ctx l -> psubst false m (fun x -> x) l
;;
projects / helm.git / blobdiff